The present invention relates to the assembling of spectacle lenses by eyecare professionals which previously have been ground to order by wholesale laboratories. This new system allows retailers to give "while you wait" service and has particular utility when multi-focal segments, progressive or blended additions, abrasion resistant coatings, anti-reflection coatings, asphericity, photochromics or other tints, polaroid filters, or other features are needed in addition to standard single vision focussing power.
Eyecare professional retailers including opticians, optometrists and ophthalmologists often carry an inventory of finished single vision prescription lenses in-house. They are able to deliver about 30% of their patient's orders from inventory by selecting the appropriate lens and edging them into the selected frames chosen by individual patients.
The remainder of their orders are sent to wholesale grinding labs for processing. Wholesale lab grinding is necessary because many prescriptions require features beyond single vision focussing power that make inventorying them impractical and too expensive. Because the number of individual permutations is nearly infinite, wholesale grinding labs carry an inventory of semi-finished blanks in a sufficient variety to cover most orders. Each category of semi-finished blank covers a huge variety of individual prescription possibilities.
The problems with this state of the art are varied. Individually ground prescription lenses are subject to variations in power, thickness and optical center location because of the complex process needed. The state of the art does not allow all lenses to be finished with exact or often tolerable specifications. This same complex process is expensive, cost inefficient and creates delays in delivery usually from 3 days to 2 weeks. In addition patient pressure for delivery often forces retailers to dispense eyeglasses that are less than optimum with respect to their specifications. This often causes eye strain, headaches, and partial loss of visual function.
Typical prior art patents include U.S. Pat. Nos. 993,812; 1,267,014; 1,304,421; 1,948,636; 2,033,101; 2,330,663; 2,611,294; 3,248,460; 3,617,116; 3,628,854; 3,702,218; 3,771,858; 3,904,281; and 3,917,766.
It would, therefore, be highly desirable to provide the spectacle retailer with lens covers which carry the particular bifocal, trifocal, special vocational or aspheric correction required by that particular patient. Prior art necessitated the use of a grinding laboratory because it would be impossible to carry in stock all the possible combinations of prescriptions, in addition to all the possible bifocal, trifocal, special vocational or aspheric locations resulting from each patient's particular facial and ocular measurements.
Attempts have been made to respond to this problem by providing composite lenses as represented by the following patents: U.S. Pat. No. 4,547,049; U.S. Pat. No. 4,576,623; U.S. Pat. No. 4,645,317; U.S. Pat. No. 3,877,798; and Japan 552-10742. However, these have not been entirely successful for a variety of reasons including the difficulty of forming the composites use of expensive equipment, inconvenience, high cost and the limited efficacy thereof.
Accordingly, it is a principal object of the present invention to provide eyecare professionals with a new system which allows the simple, convenient and expeditious assembly of spectacle lenses previously ground to order.
It is a still further object of the present invention to provide a combination eyeglass lenses as aforesaid which will allow eyeglass retailers to readily provide "while you wait" service for a wide variety of prescriptions, including multi-focal segments, progressive or blended additions, abrasion resistant coatings, anti-reflection coatings, asphericity, photochromics or other tints, polaroid filters, or other features needed in addition to standard, single vision focussing power.
A further object of the present invention is to provide the eyeglass retailer with very inexpensive lens over-lays which can be combined with his own in-house stock single vision lenses to create a simply prepared, large inventory of spectacle lenses at a reasonable cost.
A further object of this invention is to provide the patient with prompt delivery and fitting of their prescription eyeglasses even when complex additions are involved, and at a substantially reduced cost because all the fabrication can be done on the premises of the eyeglass retailer.
Further objects and advantages of the present invention will appear hereinbelow.